The race to replace gasoline

Plug-in electric cars like the Chevy Volt are among the frontrunners to replace traditional automobiles, but other energy technologies are also in the race.

Will electric cars take over America's roads? How about natural gas, or biofuels? Or will gasoline still be the automotive fuel of choice, despite concerns about imported oil and greenhouse-gas emissions? The nation's long-term energy future is still up for grabs, but a spate of recent reports suggest that big changes are on the way.

The first mass-market, highway-ready plug-in electric vehicles are already making their way to drivers' garages, although the production pipeline for Chevrolet Volts and Nissan Leafs may not be moving as fast as would-be buyers hoped. Toyota's plug-in Prius, the Ford Focus Electric and other electric entrants are due to join the Volt and the Leaf by the end of the year. But it's not yet clear whether electric vehicles, or EVs, will win out in the marketplace.

The big issue is batteries. As long as the cost of onboard electric power is high, compared to the cost of gasoline, buying an EV will never make sense based on fuel savings alone. A couple of years ago, the National Research Council estimated that providing enough battery power for 10 miles of electric driving would cost $3,300, and a 40-mile all-battery range (such as the Volt's) would add $14,000 to the cost of a car. Today, the battery pack for 200 miles of driving would add $20,000, says Kristin Persson, a researcher at the Lawrence Berkeley National Laboratory.

Scientists are focusing on making batteries work "longer, safer, cheaper," Persson said at last weekend's meeting of the American Association for the Advancement of Science in Washington. But she doesn't expect the revolution to come anytime soon: Lithium-ion will be the battery technology of choice for the next 10 to 15 years, she said.

Battery evolution, not revolutionActually, battery technology is in the midst of evolution rather than revolution. For example, during the AAAS meeting, researchers from the University of Illinois at Urbana-Champaign reported on the use of chemical-laden microspheres that give worn-out batteries the chance to "heal" themselves — extending their lifetime and cutting down on the risk of battery fires.

Another research group has developed an advanced lithium-ion battery that can store more power and operate efficiently over a wider range of temperatures. "To our knowledge, a lithium-ion battery having this unique electrode combination has so far never been reported," the researchers said this month in the Journal of the American Chemical Society. "On the basis of the performance demonstrated here, this battery is a top candidate for powering sustainable vehicles."

Better batteries are the biggest challenge for electric vehicles, but a retooling of America's energy distribution infrastructure is another, as was pointed out last year at an MIT symposium. If the auto industry meets the Obama administration's optimistic target of putting a million advanced-technology cars on the road by 2015, that could put more of a drain on the nation's electrical grid and accelerate the rise of smart-grid technology. (In the wake of last month's State of the Union Address, the administration rolled out a fresh set of initiatives aimed at meeting that 2015 goal.)

'Fracking' for energy freedom?But even with all this effort, will electric vehicles prevail? After all, the biggest winner in last year's $10 million Automotive X Prize competition was not an electric car, but Edison 2's ethanol-powered Very Light Car — which scored 102 mpg in large part because it was made from ultra-light materials, with an ultra-efficient aerodynamic design. And in the current issue of Foreign Affairs magazine, John Deutch, a former CIA director who is now a professor at MIT, claims that the global energy landscape could well be transformed by the rapid rise of shale gas as a domestic energy source.

Vehicles powered by compressed natural gas could become more prevalent, as could gas-fired electric plants. Shale gas production comes with its own problems, of course — ranging from the environmental impact of "fracking," to the issues associated with continued greenhouse-gas emissions, to the infrastructure shifts that would be required to let drivers fuel up with natural gas instead of gasoline. But the "good news about gas" demonstrates that electric isn't the only energy technology generating buzz.

What do you think? Will your next car be a plug-in, or will you be waiting to see whether another technology wins the race to replace gasoline? Feel free to register your opinion as a comment below.